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Comment by folkrav | Hacker News Reader

Unless I had a very large library or very limited storage space and no way to expand, I'm having a hard time understanding why this would objectively really matter at the scale of a personal MP3 library. We're talking about a tiny bit under 1GB of additional data per million individual tracks.

Must have been pretty fun tracking this down, but I'm curious as to why you'd go through all this trouble. Storage is cheap, my time is not haha.

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I think I was trying to get my entire music collection to fit onto my iPod, which at that time only had 10GB of space.

And also, I love to optimize things, so it made no sense to me why squeezing 1-2 more words in the track title would inflate the file size by 4KB. As a teenager, I probably had more time on my hands back then.

It would be better to just reencode tracks with VBR capped to 224 or 160 max bitrate.

Rencoding is an awful idea.

Not really, if you take A/B/X test and realize modern codec can be transparent at low bitrate (e.g. opus@128kpbs)

opus didn't exist when people were worried about 10 gb iPods

And also can't be played on said ipods.

But AAC than MP3?

In all fairness, it wasn't that long ago Apple were still selling iPod Touch with 8GB base storage, having tons of storage is a relatively new thing for most people. But with that specific 10GB metric, I'd assume we're speaking about those earlier scrollwheel iPods.

OP specified reencoding, which probably means converting lossy to lossy. Despite the fact that modern codecs (and even mp3, LAME is transparent at V2~192kbps for most tracks and everything except killer samples at V0~256kbps) are generally very transparent at low bitrates, the same guarantee does not apply when encoding lossy to lossy.

Think about it, if transparency guarantees applied for lossy transcodes, you could encode mp3 -> mp3 thousands for times with no generational loss. This clearly isn't possible.

Of course, you could rip all your files again in a better codec, but the time required to do that is pretty intense.

> if transparency guarantees applied for lossy transcodes, you could encode mp3 -> mp3 thousands for times with no generational loss

That's not really a counterexample for the idea that one pass of lossy -> lossy reencoding doesn't necessarily mean certain doom for audio quality.

When Apple reencoded its music library, you didn't assume lossy to lossy, did you?

It would certainly not be better to crunch the quality than to remove useless zero bytes.

if you had a lossless source then sure, otherwise lossy to lossy transcoding is not great.

> As a teenager, I probably had more time on my hands back then

Ain't this the reason why most of us ended up here :)

It's all about how you value your time. These kind of quests are usually very valuable learning tool and fun. I have learned a lot with hobby projects which didn't create any value as end products but were valuable to me.

The underappreciated joy of yack shaving.

>Wait, it's yack shaving all the way down?

Always has been..

There is also a cumulative value in your knowledge and understanding when hacking on things for such specific personal niggles - which over time makes future efforts more likely to reap some combination of higher rewards, faster execution and less effort... and more often than not what we learn can be applied to our day jobs in unforeseen ways.

Having a problem organically emerge in front of us that affects us personally is just a really easy thread to pull on for learning things.

> Must have been pretty fun tracking this down, but I'm curious as to why you'd go through all this trouble.

ParseError? You recognise fun but not that it might be a reason to do something?

With the limited personal time I get these days, I tend to choose activities that are both fun and useful to me. But maybe that's just me, admittedly.

OP answered, and he was a teen back then, which may have played in the "too much time on my hands" part.

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